June 11, 1858
To the Senate of the United States:
In answer to the resolution of the Senate of the 19th ultimo, respecting the Isthmus of Tehuantepec, I transmit herewith a report from the Secretary of State, with the documents by which it is accompanied, together with the copy of a letter from the postmaster-General of the 21st ultimo to the Department of State.
JAMES BUCHANAN.
James Buchanan, Message to the Senate on the Isthmus of Tehuantepec Online by Gerhard Peters and John T. Woolley, The American Presidency Project https://www.presidency.ucsb.edu/node/202785